This invention relates to an apparatus and method for drilling a hole or bore of selected curvature through a hard substance, where the curvature is selected and effected at the use site; and more particularly to a method and apparatus for drilling such a hole through bone to enable the securing thereto of wires or sutures for example.
In the field of orthopedic surgery, it frequently occurs that a hole must be drilled through bone to enabling the securing of a filamentary member to the bone. Such holes may be necessary, for example, to secure a ligament to a bone, or to immobilize two adjacent bones either temporarily or permanently. The filamentary members used for this purpose may be thread type sutures or may be wire for example.
For many of these procedures, a straight through hole may not be suitable for the intended purpose; and furthermore may be difficult or impossible to drill in the desired relation to the member or tissue which is to be secured to the bone. A common approach to the problem is to drill two straight intersecting holes, at appropriate angles to each other. One problem associated with this is that bone is a difficult material to drill since the drills tend to wander, so that achieving the intersecting point may be somewhat difficult. Another problem associated with this technique is that if the angle of the two holes is too acute, the threading of a suture needle or of a wire may be difficult.
It may be much preferred, in some instances, to be able to drill a curved hole or bore through the bone in one continuous sweep. Furthermore, it may be desirable to be able to change very quickly the radius of curvature of the hole to be drilled. This invention is concerned with an apparatus and a method for accomplishing these purposes, the apparatus being an improvement of apparatus described in Scheller, Jr., et al, U.S. Pat. No. 4,265,231, issued May 5, 1981.
An object of this invention is to provide novel apparatus for drilling a curved hole or bore.
Another object of this invention is to provide such apparatus wherein the radius of curvature may be changed readily.
A further object of this invention is to provide such apparatus wherein a portion of the drilling apparatus may be used as a hole liner after the drilling is completed.
Still another object of this invention is to provide a novel method for drilling a curved hole or bore.
A still further object of this invention is to provide such novel method enabling the ready threading of a filamentary member through the drilled hole.
Another object of this invention is to provide a novel apparatus and method for drilling a curved hole enabling the selection of the radius of curvature of the hole, to take advantage of the sculpture of the substance to be drilled or to best adapt the hole to the intended purpose.
These objects are accomplished in an attachment for a rotary motor which includes a flexible drive shaft confined within an enclosing tubular sheath. The sheath is fabricated from a semi-rigid material, and has one end configured to be nonrotatably coupled to the rotary motor. The flexible drive shaft has means at its proximal end for coupling to the output shaft of the rotary motor, and has a dissecting tool fixed to its distal end. The dissecting tool is guided for rotation by the tubular sheath, and has an outer diameter slightly larger than that of the sheath. The proximal end of the flexible shaft is dimensioned to pass through the sheath to enable removal of the dissecting tool and shaft from the sheath.
These objects are also accomplished in a method which includes the following steps. A rotary drilling tool is driven by means of a flexible shaft. The flexible shaft is confined in a tubular guiding sheath which is formable to a selected curvature, the sheath having a smaller outer diameter than the drilling tool. The assembly is guided through the material to be drilled, with the sheath following the drilling tool. The tool and attached flexible shaft may be withdrawn from the sheath so that the sheath may be used as a liner for the drilled hole.
The novel features and the advantages of the invention, as well as additional objects thereof, will be understood more fully from the following description when read in connection with the accompanying drawings.